<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .box {
            width: 80%;
            height: 300px;
            margin: 100px auto;
            min-width: 800px;
        }
        
        .gy {
            float: left;
            height: 100%;
        }
        
        .left {
            width: 230px;
            background: skyblue;
            margin-left: -100%;
        }
        
        .center {
            width: 100%;
            background: palegoldenrod;
        }
        
        .right {
            width: 200px;
            background: paleturquoise;
            margin-left: -200px;
        }
        
        .content {
            height: 100%;
            background: palevioletred;
            margin: 0 200px 0 230px;
        }
    </style>
</head>

<body>
    <!-- 起源于淘宝，用到float浮动和margin-left -->
    <div class="box">
        <div class="gy center">
            <div class="content">nih</div>
        </div>
        <div class="gy left">niids</div>
        <div class="gy right">sdvs</div>
    </div>
</body>

</html>